Services and additional functions, which are provided by electronic devices, have been gradually extended and diversified. Electronic devices have been continuously developed in order to improve the effective value of the electronic device and in order to meet various desires of users. As an example of satisfying the user's desire, the electronic device may be wirelessly supplied with power from a charging apparatus that supplies power, and the charging apparatus may wirelessly supply power to the electronic device.
In general, a method for providing wireless charging to the electronic device includes a magnetic induction method and a magnetic resonance method. The magnetic induction method may be effectively performed in a short range, which uses an induction phenomenon between coils and uses a frequency of several KHz, and its transmission distance is normally within several centimeters. In such a magnetic induction method, when the charging apparatus and the electronic device are spaced 1 mm apart from each other, the efficiency of charging may be 90% of that of a wired charging method. With regard to the magnetic induction method, when a variable current is applied to a transmission coil, an induction current is generated in a reception coil with the same frequency by the non-radiation type of electromagnetic wave that is generated to have the same frequency as the applied variable current, thereby charging the electronic device.
In addition, the magnetic resonance method uses a resonance phenomenon between the transmission coil and the reception coil by using resonance coils, which uses a frequency of 1 to 20 MHz, and its transmission distance is normally within several meters. For example, the magnetic resonance method may use a frequency of 6.78 MHz. In such a magnetic resonance method, when the charging apparatus and the electronic device are spaced several centimeters apart from each other, the efficiency of charging may be 70% of that of a wired charging method. With regard to the magnetic resonance method, the magnetic field generated by a variable current applied from the transmission coil is applied to the resonance coil by means of an inductive coupling, and a magnetic resonance coupling occurs between the resonance coils having the same resonance frequency, and thus the induction coupling is generated in the reception coil, thereby charging the electronic device.
The above information is presented as background information only to assist with an understanding of the present disclosure. No determination has been made, and no assertion is made, as to whether any of the above might be applicable as prior art with regard to the present disclosure.